Partial nitritation and nitrogen removal of vacuum toilet wastewater from high-speed trains in a sequential batch reactor

Owing to the high contents of organics and nitrogen in vacuum toilet wastewater (VTW) generated from high-speed trains, onsite pretreatment is usually required before VTW can be discharged into municipal sewers. In this study, a partial nitritation process was stably established in a sequential batch reactor to efficiently utilize the organics in synthetic and real VTWs for nitrogen removal and to produce an effluent suitable for anaerobic ammonia oxidation. In spite of the high fluctuations of COD and nitrogen in VTW, the organics used for nitrogen removal stabilized at 1.97 ± 0.18 mg COD mg N^-1 removed, and the effluent NO₂^--N/NH₄⁺-N ratios were maintained at 1.26 ± 0.13. The removal efficiencies of nitrogen and COD were 31.8 ± 3.5% and 65.2 ± 5.3% under the volumetric loading rates of 1.14 ± 0.15 kg N m^-3 d^-1 and 1.03 ± 0.26 kg COD m^-3 d^-1 for real VTW, respectively. Microbial community analysis revealed that Nitrosomonas (0.95%-1.71%) was the dominant autotrophic ammonium-oxidizing bacterial genus, but nitrite-oxidizing bacteria, Nitrolancea, was severely inhibited, with a relative abundance less than 0.05%. The relative abundance of denitrifying bacteria increased by 7.34% when the influent was switched to real VTW. Functional profile predictions of the biomass showed that the decrease in the COD/N ratio and the switch of reactor influent from synthetic to real VTW increased the relative abundance of enzymes and modules involved in carbon and nitrogen metabolisms.

Flushing Toilets and Cooling Spaces with Seawater Improve Water-Energy Securities and Achieve Carbon Mitigations in Coastal Cities

Exploring alternative water sources and improving the efficiency of energy uses are crucial approaches to strengthening the water-energy securities and achieving carbon mitigations in sub(tropical) coastal cities. Seawater use for toilet flushing and district cooling systems is reportedly practical for achieving multiaspect benefits in Hong Kong. However, the currently followed practices are yet to be systematically evaluated for scale expansions and system adaptation in other coastal cities. The significance of using seawater to enhance local water-energy securities and carbon mitigations in urban areas remains unknown. Herein, we developed a high-resolution scheme to quantify the effects of the large-scale urban use of seawater on a city's reliance on non-local and non-natural water and energy supplies and its carbon mitigation goals. We applied the developed scheme in Hong Kong, Jeddah, and Miami to assess diverse climates and urban characteristics. The annual water and energy saving potentials were found to be 16-28% and 3-11% of the annual freshwater and electricity consumption, respectively. Life cycle carbon mitigations were accomplished in the compact cities of Hong Kong and Miami (2.3 and 4.6% of the cities' mitigation goals, respectively) but not in a sprawled city like Jeddah. Moreover, our results suggest that district-level decisions could result in optimal outcomes supporting seawater use in urban areas.

Comparing Two Methods of Reducing Hospital Toilet Aerosols

BACKGROUND

When flushed, uncovered hospital toilets have been shown to generate aerosols potentially containing bacteria, viruses, and hazardous drugs, which can be inhaled by healthcare workers and contaminate surfaces. Guidelines recommend placing a plastic-backed absorbent pad (PBP) over the toilet, although no studies have evaluated the effectiveness of this intervention.

OBJECTIVES

The purpose of this study was to evaluate the effectiveness of using a PBP versus the Splashblocker®, a solid, reusable engineering barrier control, to reduce post-flush aerosol particles.

METHODS

Aerosol measurements were taken with an optical particle counter in a bathroom testing chamber equipped with a commercial hospital toilet and flushometer valve. Three tests were performed at a height of 16 inches above the floor and 40 inches above the floor.

FINDINGS

Both the PBP and the Splashblocker significantly reduced the number of post-flush particles by more than 99% at 16 inches above the floor and 40 inches above the floor. The results indicate that both interventions are equally beneficial in reducing aerosols after flushing a hospital toilet.

Spread of flushing-generated fecal aerosols in a squat toilet cubicle: Implication for infection risk

Toilet flushing generates and spread fecal aerosols, potentially leading to infection transmission risk. Squat toilets are widely used in public restrooms in some Asian countries including China and India, and remain to be studied. Aerosol dispersion while flushing squat toilet in cubicle was visualized, while the aerosol concentrations were measured on different surfaces by monitoring fluorescence intensity through seeding simulated fluorescence feces. Flushing-generated fecal aerosols could spread to the breathing zone, deposit on floor, and partitions in squat toilet cubicles, and spread even beyond to the restroom lobby. A total of 0.24 % and 0.17 % of seeded fecal waste deposits on the floor and partition (lower than 0.20 m) for each flush. Aerosol concentration decays rapidly, with 86.8 ± 2.2 % reduction in the second minute after a previous flush compared to that in the first minute. Public toilet users are recommended to wait for 2 min after the early flush before entering the cubicle.

Sensor-based evaluation of a Urine Trap toilet in a shared bathroom

Urine diversion in a No-Mix Toilet is a promising approach for sustainable fertilizers and reduction of the nutrient load for wastewater treatment; however, user adoption remains a challenge. This study evaluates the Urine Trap, a passive No-Mix toilet design based on the teapot effect, wherein the urine stream inlet is invisible to the user and therefore it does not impact the user experience for increased adoption. This study evaluated the nutrient separation performance of a Urine Trap flush toilet in a bathroom shared by women in two sites in India. Over three different testing periods, 841 uses of this squat plate were recorded in 50 days. Analytical measurements found 36 % separation efficiency for total nitrogen (TN). While effective, the Urine Trap under test by users did not yield a 70-80 % TN separation efficiency observed under engineering characterization. High temporal resolution data from sensors on waste collection tanks, the opening of the bathroom door, and cleansing water flow were used to gain insights into hygiene practices. The data showed a frequent habit of wetting the squat plate during physiological excretion, a hygienic practice that eases cleaning but degrades the teapot separation effect of the Urine Trap design. By using sensors, we demonstrate a method to non-invasively gain quantitative insights into hygiene practices to inform sanitation technologies deployment strategies for improved outcomes.

Humans peeing: Justice-involved women's access to toilets in public spaces

Justice-involved women face myriad challenges as they negotiate the terms of community supervision and manage the long-term implications and stigma of living with a criminal record. Major tasks that women juggle include securing safe, affordable housing, finding and retaining employment, accessing physical and mental health care (including substance use treatment), and handling relationships with family, friends, children, and intimate partners. In addition to these responsibilities, women must meet their basic physiological needs to eat, sleep, and use the toilet. Women's ability to safely meet their personal care needs may impact their capacity to manage their criminal-legal challenges. This study uses qualitative methods to understand justice-involved women's lived experiences related to urination. Specifically, the study reports on a thematic analysis of 8 focus groups conducted with justice-involved women (n = 58) and the results of a toilet audit conducted in the downtown areas of the small city in the United States where the focus group participants were living. Findings suggest that women had limited access to restrooms and reported urinating outside. Lack of restroom access impacted their engagement with social services support and employment and their ability to travel through public spaces. Women perceived their public toilet options as unsafe, increasing their sense of vulnerability and reinforcing the idea that they did not have full access to citizenship in the community because of their criminal-legal involvement. The exclusion and denial of women's humanity that is perpetuated by a lack of public toilet access impacts women's psychosocial outcomes. City governments, social service agencies, and employers are encouraged to consider how lack of toilet access may impact their public safety and criminal-legal objectives and expand opportunities for people to access safe restroom facilities.

Performance exploration and microbial dynamics of urine diverting composting toilets in rural China

The ongoing "toilet revolution" in China provides new opportunities to improve the rural living environment and sanitation, and the introduction of new sanitation facilities such as urine diverting composting toilets (UDCTs) is conducive to the effective treatment and resource utilization of feces. This study revealed the degradation performance and microbial community dynamics of UDCTs and clarified the influence mechanism of fecal volume in aerobic composting treatment. The results showed that UDCTs could effectively decompose human feces, with an organic matter degradation rate of 25%⁓30%. The temperature, water content, NH₄⁺-N and nutrient accumulation were higher in the high fecal volume treatment than in the low fecal volume treatment. Bacterial community composition and structure in UDCTs varied with composting stage and fecal volume. The diversity and richness of bacterial community in compost were changed with different fecal volumes, but the dominant groups were similar. Redundancy analysis (RDA) showed that nitrogen and organic carbon were the main drivers of bacterial community changes during composting. Highly nutritious and non-phytotoxic compost products were suitable for agronomic uses. Based on these results, UDCTs can be an effective way to solve the problem of fecal pollution in rural areas, and fecal dosage is a potential influencing factor in the operation and maintenance of composting systems.

Accessibility Improvement of Public Schools Through User Involvement in JAPAN

According to the amendment (2020) of the Act on the Promotion of Smooth Transportation, etc. of Elderly Persons, Disabled Persons, etc. in Japan, public primary and junior high schools, which are newly built/renovated/extended, should be designed to be physically accessible for students with special needs. In addition, existing schools should also make efforts to improve accessibility. On this background, this paper focuses on the methods to effectively promote accessibility in schools that is achieved through user involvement for inclusive education. The survey subjects were all 164 public schools in Saitama city. A questionnaire to all schools was conducted to find out 1) the features of physical obstacles impeding inclusive education and 2) examples of user involvement in the planning stage of accessibility. In the results, accessible toilets have been installed progressively. However, inaccessible routes and spaces remained because there were no lifts in most existing schools. Regarding user involvement, a good practice was discovered in one case of restroom renovation which reflected parents' requests. In reality, because of the limitation of the budget of the municipality, it was obviously difficult to provide sufficient accessibility in all 164 schools in the short period. To achieve fully accessible schools for everyone, it is crucial to create short/mid/long-term facility management strategies and to share knowledge/skills regarding accessibility improvement among administrative officers, architects, and users, so that they can find efficient and effective ways to promote accessibility.

Gender-Neutral Toilets: A Qualitative Exploration of Inclusive School Environments for Sexuality and Gender Diverse Youth in Western Australia

School toilets have been identified by sexuality and gender diverse (SGD) students as the least safe spaces in educational institutions. They are sites of verbal, physical and sexual victimisation. Providing gender-neutral toilets in primary and secondary schools may reduce the bullying and victimisation of SGD students, particularly those who are transgender or gender-diverse. This study explored factors influencing the inclusion of gender-neutral toilets in primary and secondary schools in Western Australia. Thirty-four interviews were conducted from May to December 2020 with policy makers or practitioners (n = 22) and school staff (n = 12) in Perth, Western Australia. Interviews were conducted online and face-to-face using semi-structured interview guides. A thematic analysis of the cross-sectional qualitative data was undertaken. School staff, policy makers, and practitioners identified school toilets as sites of bullying and victimisation of SGD youth and expressed support for gender-neutral toilets as an anti-bullying strategy. Perceived barriers to introducing gender-neutral toilets in schools included financial and spatial costs, building code compliance constraints, resistance from parents and students, privacy and confidentiality concerns, and cultural appropriateness. Including gender-neutral toilets in schools may reduce school-based bullying and victimisation, and improve the mental and physical health of SGD youth.

Improving Toilet Usability and Cleanliness in Public Schools in the Philippines Using a Packaged Operation and Maintenance Intervention

This study evaluated the impact of packaged interventions for operation and maintenance (O&M) on the usability and cleanliness of toilets in public schools in the Philippines. In this cluster-randomized controlled trial, the divisions of Roxas City and Passi City were randomly assigned to the intervention or control group. Schools in Roxas City (n = 14) implemented the packaged O&M interventions; schools in Passi City (n = 16) formed the control group. Outcome variables were toilet usability-defined as accessible, functional and private-and toilet cleanliness, measured using the Sanitation Assessment Tool (SAT) and the Cleaner Toilets, Brighter Future (CTBF) instruments at baseline and at four months follow-up through direct observation of school toilets. SAT results showed that intervention schools had a 32.0% (4.6%; 59.3%) higher percentage of usable toilets than control schools at follow-up after full adjustment (p = 0.024). CTBF results found a similar result, although this was not statistically significant (p = 0.119). The percentage of toilets that were fully clean was 27.1% (3.7%; 50.6%) higher in intervention schools than in control schools after adjustment (p = 0.025). SAT results also showed an improvement in cleanliness of toilets in intervention schools compared to those in controls, but this did not remain significant after adjustment. The findings indicate that the additional implementation of O&M interventions can further stimulate progress towards reaching Water, Sanitation and Hygiene service levels aligned with the Sustainable Development Goals.

Reducing the particles generated by flushing institutional toilets

Airborne particles play a significant role in the transmission of SARS-CoV-2, the virus that causes COVID-19. A previous study reported that institutional flush-O-meter (FOM) toilets can generate 3-12 times as many droplets as other toilets by splashing (large droplets) and bubble bursting (fine droplets). In this study, an aerosol suppression lid was evaluated to measure the reduction of particles by size using three metrics; number, surface area, and mass concentrations. To quantify toilet flush aerosol over time, detailed particle size distributions (from 0.016-19.81 µm across 152 size bins) were measured from a FOM toilet in a controlled-environment test chamber, without ventilation, with and without use of the suppression lid. Prior to each flushing trial, the toilet bowl water was seeded with 480 mL fluorescein at 10 mg/mL. A high-speed camera was used to record the large droplet movements after flushing. An ultraviolet-visible spectrophotometer was used to analyze the wipe samples to evaluate the contamination on the lid. The particle number, surface area, and mass concentrations without a lid were elevated compared to a lid in the first 90 sec. Overall, the lid reduced 48% of total number concentration, 76% of total surface area concentration, and 66% of total mass concentration, respectively. Depending on the particle size, the number concentration reduction percentage ranged from 48-100% for particles larger than 0.1 µm. Large droplets created by splashing were captured by the high-speed camera. Similar studies can be used for future particle aerodynamic studies. The fluorescein droplets deposited on the lid back sections, which were closer to the FOM accounted for 82% of the total fluorescein. Based on two-way ANOVA analysis, there were significant differences among both the experimental flushes (p = 0.0185) and the sections on the lid (p = 0.0146). Future work should explore the aerosolization produced by flushing and the performance of the lid in real restroom environments, where feces and urine exist in the bowl water and the indoor ventilation system is in operation.

Shared but Clean Household Toilets: What Makes This Possible? Evidence from Ghana and Kenya

Shared sanitation facilities are not considered as basic sanitation owing to cleanliness and accessibility concerns. However, there is mounting evidence that some shared household toilets have a comparable level of service as private toilets. This study examined the factors that contribute to the quality of shared household toilets in low-income urban communities in Ghana and Kenya. The study design comprised household surveys and field inspections. Overall, 843 respondents were interviewed, and 838 household shared sanitation facilities were inspected. Cleanliness scores were computed from the facility inspections, while a total quality score was calculated based on 13 indicators comprising hygiene, privacy, and accessibility. Regression analyses were conducted to determine predictors of cleanliness and the overall quality of the shared sanitation facilities. More than four out of five (84%) shared toilets in Ghana (N = 404) were clean, while in Kenya (N = 434), nearly a third (32%) were clean. Flush/pour-flush toilets were six times (p < 0.01 aOR = 5.64) more likely to be clean. A functional outside door lock on a toilet facility and the presence of live-in landlords led to a threefold increase (p < 0.01 aOR = 2.71) and a twofold increase (p < 0.01 aOR = 1.92), respectively in the odds of shared sanitation cleanliness. Sanitation facilities shared by at most five households (95% CI: 6−7) were generally clean. High-quality shared toilets had live-in landlords, functional door locks, and were water-dependent. Further studies on innovative approaches to maintaining the quality of these high-quality shared toilets are needed to make them eligible for classification as basic sanitation considering the increasing reliance on the facilities.

Toilet Injuries Presenting to Emergency Departments, 2000-2019: A Different Game of Thrones

OBJECTIVE

Toilet training is a major developmental milestone. Unsupervised periods combined with immature gross and fine motor skills may lead to toddler injuries during toilet training. Our aim was to investigate toilet-related injuries (TIs) in children.

METHODS

Data from the National Electronic Injury Surveillance System were used to evaluate emergency department encounters of children ages 0 to 6 years with TI from 2000 to 2019.

RESULTS

There were an estimated 142,606 children (95% confidence interval, 115,599-168,613) who presented to the emergency department for TI. Toilets were involved in 95% of injuries, and other potty chairs (PCs) involved 5% of injuries. Children had higher odds of sustaining head injury while using a toilet versus PC (adjusted odds ratio = 1.91; 95% CI, 1.06-3.45).

CONCLUSIONS

Toilet-related injuries present a high burden of risk to young children. Our data support that the safest vessel for use in toilet training is a PC/training seat as opposed to the toilet.

Effects of face masks and ventilation on the risk of SARS-CoV-2 respiratory transmission in public toilets: a quantitative microbial risk assessment

Public toilets may increase the risk of COVID-19 infection via airborne transmission; however, related research is limited. We aimed to estimate SARS-CoV-2 infection risk through respiratory transmission using a quantitative microbial risk assessment framework by retrieving SARS-CoV-2 concentrations from the swab tests of 251 Thai patients. Three virus-generating scenarios were investigated: an infector breathing, breathing with a cough, and breathing with a sneeze. The infection risk (95th percentile) was as high as 10^-1 with breathing and increased to 1 with a cough or a sneeze. No significant gender differences for toilet users (receptors) were noted. The highest risk scenario, namely breathing with a sneeze, was further evaluated for risk mitigation measures. Mitigation to a lower risk under 10^-3 succeeded only when the infector and the receptor both wore N95 respirators or surgical masks. Ventilation of up to 20 air changes per hour (ACH) did not decrease the risk. However, an extended waiting time of 10 min between an infector and a receptor resulted in approximately 1.0-log₁₀ further risk reduction when both wore masks with the WHO-recommended 12 ACH. The volume of expelled droplets, virus concentrations, and receptor dwell time were identified as the main contributors to transmission risk.

Public toilets from the perspective of users: a case study in a public place, Brazil

Public toilets are essential infrastructure to guarantee the right to sanitation in public spaces and, in more general terms, the right to inclusive and sustainable cities. Moreover, since the equipment has a direct user interface, it is important to understand their demands and needs. Given this, the present research aims to understand the perspective of public toilet users on the Pampulha Lake Shore (PLS), a public touristic place in Belo Horizonte, Brazil. For that, observations and semi-structured interviews were carried out with different public toilet users. In addition, comments posted on the Google Local Guides tool of Google Maps were used as a secondary database for understanding users' experience of PLS toilets. The analysis made it possible to identify aspects related to availability, quality (health and hygiene), security, and accessibility. Collected data showed how the conflicting choice of whether or not to use the toilet was directly related to the health and conservation of the urban equipment and interfered with social and leisure prospects. On the whole, the importance of the user's perspective was highlighted in this study with emphasis on elaborating adequate urban planning with regard to health, sanitation, and accessibility issues.

The rate of vermi-compost accumulation within 'Tiger Toilets' in India

Tiger Toilets use a worm-based ecosystem to degrade human waste and have recently been demonstrated as a cost-effective innovation in on-site sanitation. The benefits over traditional pit latrines include slower fill rate, fewer odours, and safer emptying. However, a question remains around how to measure the rate of accumulation of vermi-compost and predict the fill rate into the future. In this study, fifteen Tiger Toilets of varying installation ages in the villages of Jejuri, Bhalgudi and Walhe/Adachiwadi, in Maharashtra province, India were investigated to determine the rate of filling. A laser measure was used to define cross-sections of the depth to vermi-compost layers within the Tiger Toilet digesters. Bench-scale column tests were used to estimate liquid infiltration rates from the digesters into the surrounding soils. Changes over time in the interior digester conditions were photographed and a video camera was installed in selected digesters to confirm and observe the worm activity in situ under red light. Calculated fill rates of the Tiger Toilets were significantly lower compared to estimated fill rates of traditional pit latrines of a similar size and usage rate. The infiltration of the liquid fraction of the waste into the surrounding soil was observed to be a key factor in filling.

Microbial contamination of hands with or without the use of bidet toilets (electric toilet seats with water spray) after defecation

Bidet toilets (electric toilet seats with water spray) are increasing in popularity worldwide. However, the extent of reduction of microbial contamination of the hands with the use of bidet toilets after defecation is unclear. Microbe contamination of the hands with and without the use of bidet toilets after defecation was examined in 32 nursing students. Double gloves were worn on the dominant hand and four layers of toilet paper were used to wipe the buttocks after defecation, and microbe contamination of the second glove (outer glove) of the double gloves was examined. The volunteers were free to select the flow volume, wash time of the bidet, and the type of bidet. Without the use of a bidet toilet, the average value ± standard deviation of the number of microbes attached to the gloves was 39,499.3 ± 77,768.3 colony forming units (cfu)/glove; however, it was 4,146.9 ± 11,427.7 cfu/glove when the bidet toilet was used. The number of microbes adhering to gloves was significantly reduced when a bidet toilet was used (p < 0.00001, Wilcoxon signed-rank test).

Poor awareness and attitudes to sanitation servicing can impede China's Rural Toilet Revolution: Evidence from Western China

The ongoing Toilet Revolution in China offers an opportunity to improve sanitation in rural areas by introducing new approaches, such as urine source separation, that can contribute to achieving SDG6. However, few studies have systematically assessed the social acceptability of managing human excreta collected in new sanitation systems. Therefore, in this study we performed face-to-face interviews with 414 local residents from 13 villages across three provinces in western China, to analyze the current situation and attitudes to possible changes in the rural sanitation service chain. We found that the sanitation chain was predominantly pit latrine-based, with 86.2% of households surveyed collecting their excreta in a simple pit, 82% manually emptying their pits, and 80.2% reusing excreta in agriculture without adequate pre-treatment. A majority (72%) of the households had a generally positive attitude to production of human excreta-derived fertilizer, but only 24% agreed that urine and feces should be collected separately. Multivariate logistic regression indicated that three factors (level of education, number of permanent household residents, perceived social acceptability) significantly influenced respondents' attitudes to reuse of excreta, although only perceived social acceptability had a high strength of association. Overall, our survey revealed that rural households often misuse toilet systems, fail to comply with government-specified sanitation guidelines, have low awareness of alternative solutions, and are over-reliant on the government to fix problems in the service chain. Thus while new sanitation technologies should be developed and implemented, information campaigns that encourage rural households to manage their excreta safely are also important.

Mitigating the toilet flush noise: A psychometric analysis of noise assessment and design of labyrinthine acoustic Meta-absorber for noise mitigation

Modern apartments in major cities are usually made of lightweight structures with inadequate acoustic properties, leading to a growing number of noise complaints by residents of inadequate sound insulation in high-rise buildings. When a toilet is flushed, loud and irregular sounds like humming, gurgling, or bubbling, "explosive" fury from vacuum-assisted toilets are generated. Though these toilet flushing sounds are not very harmful, they can still be perceived as nuisances by users nearby. The toilet flushing noise has posed a serious concern among apartment occupants and adjacent residents, causing health problems like sleep disturbance and irritation. In this study, the psychoacoustical investigations have been performed in four stages. In the first stage, the toilet flushing noise was recorded for several toilets with two designs: a close-coupled floor-mount toilet and a back-to-wall mount toilet. The second stage evaluated the physical and psychoacoustical characteristics of those recorded flushing sounds using psychoacoustic analysis software. The noise qualities were determined in the third stage by assessing autocorrelation function/interaural cross correlation function factors from the post-processed recorded sound data. Finally, we designed and successfully demonstrated an innovative acoustic meta-absorber prototype for mitigating the toilet flushing noise. The results have revealed a significant reduction in loudness because of meta-absorbers.

What is the risk of acquiring SARS-CoV-2 from the use of public toilets?

Public toilets and bathrooms may act as a contact hub point where community transmission of SARS-CoV-2 occurs between users. The mechanism of spread would arise through three mechanisms: inhalation of faecal and/or urinary aerosol from an individual shedding SARS-CoV-2; airborne transmission of respiratory aerosols between users face-to-face or during short periods after use; or from fomite transmission via frequent touch sites such as door handles, sink taps, lota or toilet roll dispenser. In this respect toilets could present a risk comparable with other high throughput enclosed spaces such as public transport and food retail outlets. They are often compact, inadequately ventilated, heavily used and subject to maintenance and cleaning issues. Factors such as these would compound the risks generated by toilet users incubating or symptomatic with SARS-CoV-2. Furthermore, toilets are important public infrastructure since they are vital for the maintenance of accessible, sustainable and comfortable urban spaces. Given the lack of studies on transmission through use of public toilets, comprehensive risk assessment relies upon the compilation of evidence gathered from parallel studies, including work performed in hospitals and prior work on related viruses. This narrative review examines the evidence suggestive of transmission risk through use of public toilets and concludes that such a risk cannot be lightly disregarded. A range of mitigating actions are suggested for both users of public toilets and those that are responsible for their design, maintenance and management.

Access to sanitary toilets and health outcomes: A panel data analysis using two-way fixed effects model

Based on the data regarding the renovation of the toilets of 30 provinces (municipalities) in rural China from 2005 to 2017, this study utilized a two-way fixed effect model to empirically test the impact of access to sanitary toilets on health, which include intestinal infectious diseases (consisting of hepatitis A, dysentery, and typhoid) and child mortality (consisting of perinatal mortality, infant mortality, and the mortality rate of children under 5). This study attempted to assess the health outcomes of the "toilet revolution" in rural China. The results showed that: (1) Access to sanitary toilets effectively reduced the incidence of hepatitis A and dysentery. For every 1% increase in the rate of access to sanitary toilets, the incidence of hepatitis A was reduced by 5.6%, and the incidence of dysentery was reduced by 36.5%. (2) Access to sanitary toilets does not significantly reduce child mortality. (3) There are obviously regional differences in the impact of access to sanitary toilets on the health outcomes. The renovation of sanitary toilets has shown the most significant effect on reducing the incidence of intestinal infectious diseases in the central region as well as the effect on reducing child mortality in the western region. It is implied that the health outcomes of China's "toilet revolution" may provide supporting evidence and experience for other developing countries and regions in implementing toilet renovation projects.